Reciprocating piston engine

ABSTRACT

A rotary engine comprises a rotor defining interiorly a plurality of radially disposed cylinders and a reciprocating, fluid-pressure-driven piston in said cylinder. Each piston carries a cross pin extending parallel to the axis of rotation and projecting through a radially elongated slot in the rotor. Rotation of the rotor about its axis is effected by the interaction of the cross pins with one or more fixed elliptical tracks disposed in planes normal to the axis of rotation.

United States Patent 1191 Sullivan 1 1 Jan. 16, 1973 RECIPROCATINGPISTON ENGINE James P. L. Sullivan, P. O. Box 3241, Scottsdale, Ariz.85257 Filed:- July 31, 1970 Appl. No.: 59,876 I Inventor:

US. Cl. ..9l/496 Field of Search ..-..91/6.5, 474, 496, 498, 491

References Cited UNITED STATES PATENTS 3,093,079 6/1963 Graham ..9I/4741,674,374 6/1928 Papackoua FOREIGN PATENTS OR APPLICATIONS 1,911,74710/1969 Germany ..9l/496 544,410 4/1942 Great Britain ..9l/496 PrimaryExaminer-William L. Freeh Attorney-Cushman, Darby & Cushman [5 7ABSTRACT A rotary engine comprises a rotor defining interiorly aplurality of radially disposed cylinders and a reciprocating,fluid-pressure-driven piston in said cylinder. Each piston carries across pin extending parallel to the axis of rotation and projectingthrough a radially elongated slot in the rotor. Rotation of the rotorabout its axis is effected by the interaction of the cross pins with oneor more fixed elliptical tracks disposed in planes normal to the axis ofrotation.

5 Claims, 12 Drawing Figures PATENTEDJAHIEISYS 3.710.691

sum 1 [1F 3 FIG.|

INVENTOR. fins; P1. .5711 um Fl G.2 gum g ae/vzvs RECIPROCATING PISTONENGINE This invention relates to reciprocating-piston, rotary machinessuitable for converting fluid pressure to rotary power or utilizingrotary power to pump or com press a fluid.

The type of machine under consideration has some features in common withthe type of machines disclosed in US. Pat. Nos. 1,475,509 and 1,627,403.These known machines include a rotor fixed to and rotatable with a shaftand defining a plurality of internal cylinders arranged with their axesdisposed in a radial pattern with respect to the axis of rotation. A

reciprocating piston is disposed in each cylinder and carries at alocation intermediate its ends a cross pin which extends parallel to theaxis of rotation and which projects through and rides along a radialslot in the rotor. The ends of the pins ride within a stationary endlessraceway or groove of such shape that linear movement of the pistons,under the action of steam pressure or combustion pressure against oneface of the pistons, is converted to torque on the rotor. Alternativelyas disclosed in US. Pat. No, 1,475,509, by applying rotary power to therotor the pistons will be reciprocated so as to act as a pump,compressor or the like.

The present invention represents improvements over the above-describedprior machines in that constructional features are incorporated whichincrease the versatility, performance and efficiency of the machine andwhich increase the power/weight ratio when the machine is employed as amotor. The improved constructional features relate primarily to pistonand cylinder configuration and to special valving arrangements by whichfluid is introduced to and exhausted from the cylinders. Oneparticularly important feature renders the pistons double-acting in thesense that the pistons can be driven in two directions by the drivingfluid.

The invention will be-further understood from the following detaileddescription of an exemplary embodiment which functions as a motor, takenwith the drawings in which:

FIG. 1 is a simplified perspective view, partly broken away, of a fluidpressure motor embodying the principles of the present invention;

FIG. 2 is a sectional view on an enlarged scale taken on the line 2-2 ofFIG. 1;

FIG. 3 is a sectional view taken on the line 3-3 of FIG. 2;

FIG. 4 is a fragmentary plan view of part of the stator assembly of themotor showing the raceway;

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 3;

FIGS. 6 and 7 are fragmentary sectional views taken on the lines 6-6 and77,.respectively, of FIG. 5; and

FIGS. 8a through 8e are diagrammatic illustrations of the operation ofone of the pistons.

As best seen in FIGS. 1, 2 and 3 the motor embodiment disclosed thereinincludes a rotor 10 fixed to and rotatable with a power-output shaft 12and a stator housing 14 enclosing the rotor 10 and supporting the shaft12 by means of suitable bearings 16. Formed within the rotor 10 are aplurality of cylinders 18 disposed with their axes extending radiallywith respect to the shaft .12. A double-acting piston 20 reciprocates Iwithin each cylinder 18. Affixed to each piston 20 at a locationintermediate the ends of the latter is a crosspin assembly 22 whichextends parallel to the shaft 12 and which has opposite free endsprojecting through radially elongated slots 24 in opposite sides of eachcylinder wall.

In the illustrated embodiment all the cross-pin assemblies 22 are guidedto move in a common nonlinear endless path which is disposed in a planenormal to the axis of rotation of the rotor 10 in amanner such that theinteraction of the pin assemblies 22 with a fixed guide means convertsreciprocation of the pistons 20 to torque on the rotor 10. As shown,this may be accomplished by receiving the free ends of each cross-pinassembly 22 within a pair of spaced-apart, parallel elliptical grooves26 cut in opposite interior faces of the stator housing 14 and disposedsymmetrically with respect to the shaft 12. The grooves 26 may bechannel-shaped in-transverse cross-section, and the sides of the endportions of the cross-pins 22 may be provided with roller bearing meansin the form of oppositely disposed rollers 28, 30 which engage the sidesof the grooves 26. As seen in FIG. 3 the body or shank portion of eachpin assembly 22 may be similarly provided with rollers 32 for engagingthe sides of the slots 24 in the rotor 10. In each case the rollers arepartially disposed in appropriate recesses in the pins.

As-will be understood, one side of a given pin assembly 22 will pushagainst the inner channel wall 26a during inward movement of therespective piston 20 and its other side will push against the outerchannel wall 26b during outward movement of the respective piston 20. Inthe illustrated embodiment there are four cylinders 18 arranged inopposed pairs, the pistons of each pair being guided by the grooves tomove inwardly and outwardly in unison and in the opposite direction fromthe pistons of the other pair. As shown in FIG. 2 the right and leftpistons20 are in their outermost position, as determined by thehorizontally spaced apart ends of the groove 26 (FIG. 4), and the upperand lower pistons 20 are in their innermost position. In operation fluidpressure is delivered simultaneously to the inner faces of the outpistons and to the outer faces of the in pistons. At each quarterrevolution of the .rotor 10 the pressure is released'and applied to theopposite faceof each piston with the result that there are 16 pressurestrokes per revolution (four pressure strokes per piston perrevolution).

Referring to the double-acting characteristic of the pistons 20 it willbe seen that each cylinder is in communication with four fluid passages34,36, 38 and 40. Passages 34 and 36 extend, respectively, from theinner endand the outer end of the respective cylinder 18 to a centralcylindrical bore 42 disposed on the axis of rotation of the rotor 10. Inthe illustrated embodiment the bore 42 is a hollow tubular portion ofthe shaft 12. The

passage 38 extends from the side wall of the cylinder 18 at a locationnear its inner end to the periphery of the rotor 10. The passage 40extends from the side wall of the cylinder 18 at a location near itsouter end to the periphery of the rotor 10. In operation of the motorthe passages 38 and 40 serve as primary exhaust outlets for passages 34and with the four passages 36 during rotation of the shaft 12 and rotor.The valve member 44 has an axial bore 46 in communication with aconventional fluid pressure connection 48 located outside the statorhousing 14. Two transverse passages 50 and 52 are provided through thevalve member 44 at axially spacedapart locations. The passage 50 isdisposed adjacent the inner ends of the four passages34 which as seen inFIGS. 3 and 6 are disposed symmetrically with respect to the shaft 12,so that during rotation of the rotor 10 the bore 46 of the valve member44 communicates first with the inner ends of two opposite cylinders 18and then the inner ends of the other two opposite cylinders 18.Similarly, the passage 52 is disposed adjacent the symmetricallyarranged inner ends of the four passages 36 so as to place the valvebore 46 first in communication with the outer ends of two oppositecylinders 18 and then with the outer ends of the other two oppositecylinders 18. In the position of the valve member 44 shown in FIG. 5 itwill be seen that the valve bore 46 is in communication with the innerends of two of the cylinders 18 and the outer ends of the other twocylinders with the result that all four pistons 20 are being acted on bypressure fluid simultaneously.

The passages 34 and 36 also serve as secondary exhaust outlets, as willbe described hereinafter. To this end the valve member 44 is providedwith two external spiral grooves 54 and 56 which communicate at theirouter ends with an annular space 58 defined between the outer end of thevalve member 44 and 'the stator housing 14. As seen in FIG. 6 thegrooves 54 and 56 place the inner ends of the passages 34 of twoopposite cylinders 18 in communication with the atmosphere while theinner ends of the other two passages 34 are receiving pressure fluidthrough the valve bore 46 and passage 50. The grooves 54 and 56 performa similar function for the inner ends of the other passages 36, as seenin FIG. 7.

The passages 38 and 40 serve as exhaust outlets, and in the illustratedembodiment they lead to the space defined between the rotor 10 and thestator housing 14. Each pair of passages 38 and 40 is shown as havingbeen drilled from a common point on the periphery of the rotor 10 as asimplified manufacturing technique, but this feature is not critical.Exhaust fluid leaves the stator housing 14 through a suitable fitting60.

The sequence of operation of the pistons is illustrated in FIGS. 8athrough 8e. The position of the piston 20 in FIG. 8a corresponds to theposition on the left-hand piston 20 in FIG. 2 wherein it is in its outerposition, as is the opposed piston at the right side of FIG. 2. Theother two pistons, at this stage, are in their inner positions.

Referring specifically to FIG. 8a the piston 20 therein has just arrivedat its outer position at which point the rotation of the rotor 10 hasjust closed the inner end of the passage 34 at the valve member 44 sothat pressure fluid no longer flows into that passage. At this time thepiston20 has uncovered the inner end of the passage 38 to permit primaryexhaust of compressed fluid through the passage 38 to the exterior ofthe rotor 10. Upon slight additional rotation of the rotor 10 the innerend of the passage 36 opens to allow pressure fluid from the valve bore46 to enter the left end of the cylinder 18 to begin pushing the pistonto the I right, as illustrated in FIG. 8b. Simultaneously the innermember 44 by This will exchange the positions of.

end of the passage 34 arrives at the location of the groove 56 in theexterior of the valve 44, as shown in FIG. 6, so that secondary exhaustoccurs as the fluid in the cylinder 18 to the right of the piston 20 isforced outwardly through the annular space 58 around the valve member 44to the exterior of the stator housing 14.

FIG. 8c illustrates the position of the piston 20 at V4 revolution ofthe rotor 10 from the FIG. 8a position. At this point the inner end ofthe passage 36 becomes closed at the valve member 44, and the piston 20has uncovered the outer end of the passage 40 to permit primary exhaustto the exterior of the rotor 10. The piston has now undergone twocomplete pressure strokes. Upon slight further rotation of the rotor 10,pressure fluid enters the inner end of the passage 34 from the valvebore 46, and the piston begins to move to the left, closing the outerend of the passage 40, as seen in FIG. 8d. Simultaneously the inner endof the passage 36 opens to' the groove 54 in the valve member 44 topermit secondary exhaust to the exterior of the stator housing 14.

At h revolution of the rotor from the FIG. 8a position the pistonarrived at its outer position, as shown in FIG. 8a, and theabove-described cycle begins to repeat. Since each of the four pistons20 receives four pressure strokes per revolution of the rotor 10, thereare 16 total pressure strokes appliedper revolution.

From FIG. 2 it will be seen that one pair of opposite pistons 20 movesinwardly simultaneously with outward movement of the other pair and thatpressure fluid is applied to all four pistons at the same time.

The conversion of linear movement of the pistons 20 to rotation of therotor 10 by the interaction of the pin assemblies 22 and the inner andouter walls26a and 26b of the fixed groove 26 is self-evident andrequires no detailed discussion.

The machine may also be employed as a pump or compressor by connectingthe fitting 48 to a source of fluid and by applying torque to the rotorshaft 12 with a motor. In this mode of operation inward movement of theright and left pistons 20, as illustrated in FIG. 2, will draw fluidinto the outer ends of these cylinders along a path defined by thepassages 46, 52 and 36. Simultaneously, outward movement of the othertwo pistons 20 will draw fluid into the inner ends of these respectivecylinders along a path defined by the passages 46, 50 and 34. Thisoutward movement pumps fluid from the outer ends of these cylindersthrough the passages 40 for a portion of the stroke and through thepassages 36 and the groove 54 and into the annular space 58 for theentire stroke. The inward movement of the first pair of pistons pumpsfluid through the passages 38 for a portion of the stroke and throughthe passages 34 and the groove 56 and into the annular space 58 for theentire stroke. The fluid that is pumped outwardly through the passages38 and 40 leaves the machine through the fitting 60 and may be combinedby means of suitable piping with the fluid which leaves the machine byway of the annular space 58.

In order to reverse the direction in which the rotor shaft 12 is drivenit is necessary only to change the rotational position of the stationarycylindrical valve the exhaust ports and pressure ports, as will beevident from inspection of FIGS. 5, 6 and 7. The valve member 44 carriesa disc 70 from which a pointer 72 extends in a radial direction. Theassembly of valve member 44, disc 70 and pointer 72 is normally held ina fixed position by two cap screws 74 which pass through arcuate slots76 in the disc 70 into threaded engagement with the stator housing 14.Rotational adjustment of the valve member 44 may be made by looseningthe screws 74, manually rotating the pointer 72 and tightening thescrews 74.

The above-described modes of operation occur when the stator housing 14is fixed to a frame or other support. A different mode of operation inwhich the housing 14 rotates may be obtained by securing the shaft 12against rotation and removing restraints from the housing 14. In thismode the torque produced by the interaction of the cross-pin assemblies22 and the elliptical grooves 26 will cause the housing to rotatealthough the basic principles of operation are the same as for theprevious modes. When the rotating housing mode is employed the housing14 will generally be constructed in a circular shape about the axis ofrotation so that the housing 14 can be fitted with external peripheralgear teeth or with fan blades or otherwise adapted to various drivingconfigurations.

What is claimed is: 1

1. A rotary machine comprising: rotor means mounted for rotation aboutan axis passing therethrough, said rotor including a shaft and a body,said body defining a plurality of cylinders arranged radially withrespect to said axis of rotation, each of said cylinders having a closedinner end and a closed outer end; a reciprocating piston disposed withineach cylinder, each of said pistons carrying intermediate its ends across-pin extending parallel to said axis of rotation and having an endportion projecting through a radially elongated slot in said rotor body;stator means defining fixed non-linear endless track means cooperatingwith the end portions of said cross-pin of each piston in a manner suchthat the interaction of said cross-pins with said fixed track meanscauses reciprocation of said pistons to occur simultaneously withrotation of said rotor means; said rotor means having first and secondpassages therethrough associated with each cylinder, said first passagehaving an outer end in communication with the outer end of therespective cylinder and said secondpassage having an outer end incommunication with the inner end of the respective cylinder, each ofsaid passages having an inner end in communication with a central borewithin said rotor means, said bore being coaxial with said axis ofrotation; and valve means associated with said bore for alternatelyclosing the inner end of each passage and placing said inner end incommunication with the exterior of said valve means in a predeterminedmanner upon rotation of said rotor means whereby each of said passagesmay be placed in communication with a source of fluid located exteriorlyof said valve means.

2. A rotary machine as in claim 1 including anti-friction roller meanscarried by said cross pins intermediate their ends for engagement withthe walls of the slots in the rotor body and anti-friction roller meanscarried by the endportions'of said cross-pins for engagement with saidendless track means.

3. A rotary machine comprising: rotor means mounted for rotation aboutan axis passing therethrough, said rotor means defining a plurality ofcylinders arranged radially with respect to said axis of rotation, eachof said cylinders having a closed inner end and a closed outer end; areciprocating piston disposed within each cylinder, each of said pistonscarrying intermediate its ends a cross-pin extending parallel to saidaxis of rotation and having an end portion projecting through a radiallyelongated slot in said rotor means; stator means defining fixednon-linear endless track means co-operating with the end portions ofsaid cross-pin of each piston in such a manner that the interaction ofsaid cross-pins with said fixed track means causes reciprocation of saidpistons to occur simultaneously with rotation of said rotor means; saidrotor means having first, second, third and fourth passages therethroughassociated with each cylinder, said first and second passages havinginner ends communicating, respectively, withopposite ends of therespective cylinder and outer ends communicating with a common bore onthe axis of said rotor means, said third passage having one end at theexterior of said rotor means and another .end which is in communicationwith the side of the respective cylinder at a location near oneendthereof so as to be alternately opened and closed by the respectivepiston during reciprocation, said fourth passage having one .end at theexterior of said rotor means and another end which is in communicationwith the side of the respective cylinder at a location near the oppositeend thereof so as to be alternately opened and closed by the respectivepiston during reciprocation; and valve means associated with said innerends of said first and second passages, said valve means defining afluid inlet and a fluid outlet and being operable sequentially toconnect each inner end of said first and second passages with said fluidinlet, to close said inner endand to connect said inner end with saidfluid outlet, whereby an external source .of fluid may be placed incommunication with said first and second passages and hence with theopposite ends of each piston.

4. A rotary machine as in claim 3 wherein said valve means includes astationary cylindrical element disposed on the axis of rotation of therotor, said valve element having a longitudinal bore and two spacedapart transverse passages each connecting the bore- ,with the peripheryof said element, the apertures associated with the inner ends of thecylinders being c.--a plurality of cylindersformed within said rotorhousing, said cylinders arranged radially with respect to the axis ofrotation, said cylinders having closed inner and outer ends and aradially elongated slot associated with each cylinder and arranged tocommunicate between said cylinders and the exterior of said rotorhousing,

d. a reciprocating piston disposed within each of said cylinders,

a cross-pin mounted intermediate the ends of each of I said pistons,said cross-pins extending exteriorly of said rotor housing through theradial slot, said pins extending parallel to the axis of rotation, and,

f. a first and second passageways respectively connecting the outer andinner ends of said cylinders with the central bore of said rotorhousing;

B. Stator means for containing said rotor housing, said stator meanscomprising, 7 a. a stator housing having a sealed center cavity inadapted to sequentially exhaust the inner and outer ends of saidcylinders through said'first and second passageways, the exhaustandfpressure operations being out of phase.

' t I: n

1. A rotary machine comprising: rotor means mounted for rotation aboutan axis passing therethrough, said rotor including a shaft and a body,said body defining a plurality of cylinders arranged radially withrespect to said axis of rotation, each of said cylinders having a closedinner end and a closed outer end; a reciprocating piston disposed withineach cylinder, each of said pistons carrying intermediate its ends across-pin extending parallel to said axis of rotation and having an endportion projecting through a radially elongated slot in said rotor body;stator means defining fixed non-linear endless track means cooperatingwith the end portions of said cross-pin of each piston in a manner suchthat the interaction of said cross-pins with said fixed track meanscauses reciprocation of said pistons to occur simultaneously withrotation of said rotor means; said rotor means having first and secondpassages therethrough associated with each cylinder, said first passagehaving an outer end in communication with the outer end of therespective cylinder and said second passage having an outer end incommunication with the inner end of the respective cylinder, each ofsaid passages having an inner end in communication with a central borewithin said rotor means, said bore being coaxial with said axis ofrotation; and valve means associated with said bore for alternatelyclosing the inner end of each passage and placing said inner end incommunication with the exterior of said valve means in a predeterminedmanner upon rotation of said rotor means whereby each of said passagesmay be placed in communication with a source of fluid located exteriorlyof said valve means.
 2. A rotary machine as in claim 1 includinganti-friction roller means carried by said cross pins intermediate theirends for engagement with the walls of the slots in the rotor body andanti-friction roller means carried by the end portions of saidcross-pins for engagement with said endless track means.
 3. A rotarymachine comprising: rotor means mounted for rotation about an axispassing therethrough, said rotor means defining a plurality of cylindersarranged radially with respect to said axis of rotation, each of saidcylinders having a closed inner end and a closed outer end; areciprocating piston disposed within each cylinder, each of said pistonscarrying intermediate its ends a cross-pin extending parallel to saidaxis of rotation and having an end portion projecting through a radiallyelongated slot in said rotor means; stator means defining fixednon-linear endless track means co-operating with the end portions ofsaid cross-pin of each piston in such a manner that the interaction ofsaid cross-pins with said fixed track means causes reciprocation of saidpistons to occur simultaneously with rotation of said rotor means; saidrotor means having first, second, third and fourth passages therethroughassociated with each cylinder, said first and second passages havinginner ends communicating, respectively, with opposite ends of therespective cylinder and outer ends communicating with a common bore onthe axis of said rotor means, said third passage having one end at theexterior of said rotor means and another end which is in communicationwith the side of the respective cylinder at a location near one endthereof so as to be alternately opened and closed by the respectivepiston during reciprocation, said fourth passage having one end at theexterior of said rotor means and another end which is in communicationwith the side of the respective cylinder at a location near the oppositeend thereof so as to be alternately opened and closed by the respectivepiston during reciprocation; and valve means associated with said innerendS of said first and second passages, said valve means defining afluid inlet and a fluid outlet and being operable sequentially toconnect each inner end of said first and second passages with said fluidinlet, to close said inner end and to connect said inner end with saidfluid outlet, whereby an external source of fluid may be placed incommunication with said first and second passages and hence with theopposite ends of each piston.
 4. A rotary machine as in claim 3 whereinsaid valve means includes a stationary cylindrical element disposed onthe axis of rotation of the rotor, said valve element having alongitudinal bore and two spaced apart transverse passages eachconnecting the bore with the periphery of said element, the aperturesassociated with the inner ends of the cylinders being disposed so as tocooperate periodically with the inner end of each of said first passagesand the other apertures being disposed so as to cooperate periodicallywith the inner end of each of said second passages during rotation ofthe rotor.
 5. A fluidic-pressure operated rotary machine comprising: A.Rotor means mounted for rotation about an axis, said rotor meanscomprising, a. a rotor housing having a central bore co-axial with theaxis of rotation, b. a shaft arranged within the central bore andadapted to rotate with said rotor housing, c. a plurality of cylindersformed within said rotor housing, said cylinders arranged radially withrespect to the axis of rotation, said cylinders having closed inner andouter ends and a radially elongated slot associated with each cylinderand arranged to communicate between said cylinders and the exterior ofsaid rotor housing, d. a reciprocating piston disposed within each ofsaid cylinders, e. a cross-pin mounted intermediate the ends of each ofsaid pistons, said cross-pins extending exteriorly of said rotor housingthrough the radial slot, said pins extending parallel to the axis ofrotation, and, f. a first and second passageways respectively connectingthe outer and inner ends of said cylinders with the central bore of saidrotor housing; B. Stator means for containing said rotor housing, saidstator means comprising, a. a stator housing having a sealed centercavity in which said rotor means is rotatably mounted, b. at least onenon-linear endless track formed in said stator housing and arranged toreceive said cross-pins and cooperate therewith to convert reciprocationof said pistons into rotation of said rotor housing; and, C. Stationaryvalve means mounted within said shaft and adapted to receive thefluidic-pressure and apply the pressure sequentially to the inner andouter ends of said cylinders through said first and second passageways,said valve means also adapted to sequentially exhaust the inner andouter ends of said cylinders through said first and second passageways,the exhaust and pressure operations being out of phase.